Machine for grinding balls.



0. A. scIIII/IIDI.

MACHINE FOR GRINDING BALLS.

APPLICATION FILED rsa. I6. I9Is.

Patented Dec. 28, 1915.

3 SHEETS-SHEET l.

A. SCHMIDT.

MACHINE FOR GRINDING BALLS.

APPLICATION FILED FEB. I6, I9I5.

o. A. SCHMIDT. MACHINE FOR GRINDING BALLS.

APPLICATION EILED FEB. I6. 1915' Patented 1D@@.28,1915.

3 SHEETS-SHEET 3.

M/l TNESSES x11 ernten.

@TTU ALWIN SCHMIPT, E CHELMSFORJD, ENGLAND, ASSIGNOR T0 THE HOFFMAN MANUFACTURING COMPANY LIMITED, 0F CHELMSFORD, ENGLAND. A

l MACHINE ron Granma@ `Barns.

meager.

Appucation inea February 1e, 1915. serial no. atea.

' To all whom t may concern Beit known that I, OTToALwIN SoHMru'r, a subject of the German Emperor, residing at Chelmsford, Essex, England, have inf vented a certain new and use ful llmprovement in Machines for Grindlng Balls, lof

which the following is a specification.

This invention relates to improvements in machines for grinding balls of the class in which a rotating grooved abrading or like disk works in conjunction with a similarly groovedstationary cast iron or other.

disk, the balls to be ground traveling in the grooves between the two disks and falling if desired into a hopper which is provided Vat one part of the stationary disk. In machines of this class, or where the abrading` disk is grooved, it hasv been proposed to reduce the pitch of the grooves or the distance between them to such an extent that as the grooves wear the formation of ridges is proportionately reduced, the object being to.

save trlmming of the disk at frequent4 intervals.

'llhe object ofthe present invention is to provide improved means foretl'ecting this end without the liability of wedging of the balls which will take place unless means are employed to prevent it when the grooves are so arranged.- v

Briefly the invention consists in providing means to co-ac't with a disk or disks having grooves arranged in the way above referred to', whereby some of the grooves only, or some portion of the grooves only, are utilized at one time thereby allowing the balls freedom to roll without wedging while not interfering with their action in preventing the excessive formation of ridges between the grooves owing to the fact that in the course of grinding the whole of the grooves will have been traversed by the balls.

ln the accompanying drawings there are illustrated two embodiments of the inven` :c-, showing also apart of the abrading.

tion by way of example of ways in which it may be carried into edect.

lln such drawings: Figure 1 is a general view of a ball grinding machine of a known type. Fig. 2 is a face lview of the Astationary disk looking in the direction of the arrow Fig. 1, Fig. 3 1s a section of Flg. 2 online disk. Fig. 4i is a section-of'Fig. 2 on line '3l-y showing also a part of the abrading Fig. 5-is anenlarged view partly Vin sc ctlon of aA hopper hereinafter referred to. Fig. is a similar face View of the stationary disk showlng another way of carrying out the-invention. Fig. 7 lis a section of Fig. 6 on line ema, showing also a part of the -abrading disk, Fig. 8 is a similar lview to Fig. 5, vbut showingpart only of a hop a per as used with Fig. 6, and Fig. 9 isa part of a general view of a ball grinding machine in connection with this modification.

Referring first to the form shown in Figs. 1 tov5, the complete machine comprises usually a disk 1 of abrasive material driven from a spur wheel 2 by a pulley 3 through a suitable pinion 4, and a stationary disk 5 usually of cast iron which carries the hopper 6 an'dlis 'kept pressed against the abrasive disk by means indicated by the hand wheel 7 screwed spindle 8 and spring 9. The abrasive disk 1 has a number of grooves 10 on 'its face placed as close together as possible and each half ofthe stationary disk 5 has a number of grooves 11 and 12 out of line with each otherv on 'the lower and upper -half respectively each of such grooves being thus adapted to co-act with alternate grooves only,' 1n the abrasive disk. The grooves 11 and-12 are connected at one point 'of the disk 5 by a shunting device 13 inserted in its face, while at a point preferably diametrically opposite, if the fixedpdisk is arranged with 4grooves 11,12 in halves, there may be, and is preferabhT inserted a mixing hopper 6 of some known type for the vpurpose hereinafter described, or a second shunting device must be used. The shunting device 13 is formed of three blocks 14, 15, l16, having a number of passages 17 connecting the grooves 11, 12, and therefore inclined as shown' for suchipurpose. 'lihe shunting device is formed as described in three parts for convenience onlyin manufacture and such parts are kept together by a back plate 18. and screws 19 passin into same through theplate, while screws 0 are employed for holding the plate to the back of the disk 5. rllhe object of the passages 17 being to pass the balls from a groove 11 to a groove 12, the shunting device must be arranged to pick out the balls as they travel around in the combined grooves 11, 10, and

discharge them to the combined grooves 12,'`

the space between the two disks by forming'.

the passage in blocks 14 and 16 with a ris tongue 22 and 21 respectively. Further, owing to the inclination of the'passages 17 necessary to connect `the groovesll and 12 the 'balls must be broughtaway from the face of the disk 5 otherwise theywould damage the grooves 10 of disk 1, and this isv efl'ected by causing the passages 17' to retreat from the face of the disk 5 as shown in -F ig. 4 and to approach it again only when the necessary inclination in the direction of travelhas been attained, such inclination being principally effected in the central block of the'shunting device 13 as sl` wn in Fig. 2. By this arrangement the hails which have been traveling around in the grooves 10, 11, are changed into the other sets 10, 12, the grooves 10 in the abrading disk (of which there are double the number of the grooves 11, 12) being from time to time all occupied by the balls though all such grooves 10 are not occupied at the same time. lVhat actually takes place is that with the' twelve grooves 10 shown in the disk 1, one half of the grooves say, "one, three, live, seven, nine and eleven, will be full of balls and actively grinding during their travel over one half Vof the disk 5, while one half of the grooves, say, two, fo ur, six, eight, ten, and twelve will be simllarly full and grinding during their travel over the other half of the disk 5. Thus, as each of the'complete grooves 10 in the revolving disk 1 is occupied from time to time by balls there is a partial overlapping of the grooves which such balls form in the abrasive disk, and hence ridges are prevented from forming to any extent, or are worn down as formed. In other words the twelve grooves 10, in the revolving disk 1, co-act with the grooves in the stationary disk 5 in such a way as to form complete passages, so that when balls are inserted between them only alternate grooves in the revolving disk (together with the c o-acting grooves in the stationary disk) are full of balls, those formed by the grooves 10, 12', being intermediate with those formed by the grooves 10, 11. The hopper 6 in this instance fulfils its usual functions of mixing the balls, of enabling the balls to be filled into the grooves,

for sampling, and other purposes and differs only from that usually employed by reason of the side plates 23, 23, which are inclined and replace theusual side walls of the hopper generally concentric with the grooves. It also performs the function of a shunting device as while mixing the balls it also transfersthem from the uppercoacting grooves 10. 12, to the lower co-acting grooves 10, 11. The usual deflecting edge plate 24 which assists the balls to leave the grooves and discharge into the upper race 25 of the hopper is also employed. 26 are bolts forsecuring such edge plate 24 and 27 is the lower race of the hopper into which the upper discharges, and which in turn feeds the balls back into the grooves between division plates 28 which form between them spaces corresponding to the grooves in the disk 5, the side plates 23 directing the balls to such grooves. The part 25 of the hopper is secured to the disk 5 by bolts one of which is shown at 40 and the part 27 is similarly secured by bolts which are not shown. rlhese bolts pass through brackets 41, 42, which carry thev'hopper. portions 25, 27, respectively. y

In the arrangement shown in Figs. 6 to 9, the abrading disk 1a is shown as having the same number of grooves 10a as the disk 1, which grooves are either formed or allowed to form therein, but the stationary disk 5 has also a corresponding number of grooves 11a. To operate a machine under these conditions the balls are permitted to pass only into alternate grooves in both disks for a period and are then permitted toI pass only into the intermediate grooves for another period with the result Athat an even wearing of the abrading disk' or reduction of ridges, is obtained, by the partial overlapping of the grooves which such balls may form in the abrading disk and the full surface is utilized. In this case the change is effected by means of the hopper 6a which is provided with division plates 28n dividing the hopper into one half the number of spaces 30 as there are grooves in each disk. The hopper is in addition movable radially or laterally the pitch of the grooves, for which purpose it is slidable by means of dovetails and grooves 31 in the back of the stationary disk 5, this movement being effected by means of af cam 32 on the end of the handle 33 pivoted on a spindle 34 fixed in the disk 5, such cam working in a slot 35 of the bracket .hereinafter referred to. By shifting this cam either to the right or left the correct travel of the hopper is effected. The hopper in this case is in one piece, the parts 25, 27, being carried in a single bracket 44, Figs. 8 and 9 so that the whole can slide with a movement of the handle 33. The hopper may have the usual defiecting edge plate 24 for the balls. When the machine is started the balls will run say around the grooves, one,

three, five. seven, nine, eleven. and form a corresponding set of grooves 10:L in the coacting abrading disk l or will travel in a set previously formed. After a time and preferably when the hopper has been.

emptied and withdrawn rearwardly the hopper is shifted radially exactly the pitch of the grooves so that when say a new batch of balls are now fed from the hopper they run around in grooves, two, four, six, eight, ten,twelve and form corresponding grooves ineaaea et l0n in the abrasive disk, or travel in a set previously formed. Such grooves it will be seen fall between those formed or traversed by the balls previously. After a time the hopper is shifted back again into its original position for a new batch of balls. The division plates in the hopper could of course be moved in place of the entire hopper. By this means not only do the ridges between the rows of balls in the abrasive member wear away and keep the depth of the grooves uniform, but the same happens in the case iron or like disk which likewise does not have to be turned to reduce the ridges between the grooves.

The constructions above described may be considerably modified in their details without departing from the spirit of the invention. y

What l claim is l. ln a machine for grinding balls, and i combination, a grinding body having a number of grooves formed therein lying so closely together that if they were all filled with balls, those in adjacent grooves would contact with each other and means co-acting therewith for causing the balls to travel in some of the grooves only, at one time to prevent excessive ridges being formed in the grinding body and to utilize the full surface of same.

2, ln a machine for grinding balls, and in combination, a grinding body having a number of grooves formed therein lying so closely together that if they were all filled with balls, those in adjacent grooves would contact with each other, and means co-acting therewith for -causing'the balls to travel in some portion of the grooves only, at one time to prevent excessive ridges being formed in the grinding body and to utilize the full surface of same.

3. ln a machine for grinding balls and in combination, a grinding body having a number of grooves formed therein lying so closely together that if they were all filled with balls those in adjacent grooves would contact with each other, and means co-acting therewith for causing the balls to travel in alternate grooves in the first body, and for utilizing in turn all of same so that excessive ridges are prevented from forming during grinding, and the full surface of the grinding body is utilized.

4. ln a machine for grinding balls, and in combination, two co-acting bodies adapted to grind the balls between them, means adapted to form such a number of grooves in one of same by the action of the balls, that if they were all occupied by balls those in adjacent grooves would contact with each other such means consisting of the other body which has a lesser number of grooves which are out of line with each other, and a shunt device for connecting such last named grooves and carrying the balls free of any ridges which may be forming in the first named body.

5. In a machine for grinding balls, and in combination, a grinding body having two sets of grooves each occupying a portion of its surface only and being out of line with each other, a shunt device containing a series of grooves connecting such non-linable grooves, and a second rotatable disk in which is adapted to be formed a series of complete grooves equal in number to the two sets of grooves in the first disk, and ar ranged so close together that if all were occupied by balls :those in adjacent grooves would contact with each other. l

6. In a machine for grinding balls, and in combination, two opposed bodies, one having a series of grooves on its face in the relation of two to one of the other, the grooves of they latter extending a part of the way over its face only and being out of line with each other, means at two points of the latter body for enabling the balls to pass from one non-linable groove to the other, the grooves in the first body being arranged so close together that if all were occupied by balls those in adjacent grooves would contact with' each other.

7. lin a machine for grinding balls, and in combination, two opposed disks, one having a series of grooves on its face in the relation of two to one of the other and arranged. so close together that if all were occupied by balls those in adjacent grooves would contact with each other, the grooves in the latter extending a part of the way only around the surfaceof the disk the grooves in each part being out of line with those of the other part, means at one point of the latter disk for shunting the balls to enable them to pass around the non-linable grooves, a mixing hopper at another point of the latter disk, and directing means combined with same, all co-acting with the shunting means to enable the balls to pass around the nonlinable grooves of the disk.

` 8. ln a machine for grinding balls, and in combination a grinding and a holding disk, the latter having two sets of grooves each occupying a portion of the surface only and being out of line with each other, a shunt device in the holding disk containing a series of grooves inclined to connect such nonlinable grooves and further retreating from the face of the first disk, and a second shunt device in such holding disk for further connecting such non-linable grooves, the first named disk having its grooves arranged so close together that if all were occupied by balls those in adjacent grooves would contact with each other.

9. ln a machine for grinding balls and in combination, two co-acting bodies adapted to grind the balls between them, a part carried by one body, adapted-with such body to form such a number, of grooves in the other body by the action of the balls, that if adapted to form such a number of grooves 15 1n one of same by the action of the balls that if they were all occupied by balls those in adjacent grooves would contact with each other, and a feeding device for the balls having means' for selecting the formed 2( grooves in which the balls are to travel.

In testimony whereof I have set my hand in the presence of two subscribing witnesses.

OTTO ALWIN SCHMIDT.

Witnesses:

ALFRED JOSEPH BUTLIN, ERNEST HARKER. 

